Field of the Invention
The present invention is related, in general, to coupling of multiple pipes and, more particularly, to a push connect coupling arrangement.
Description of Related Art
Prior to the advent of plastic pipe, most piping was made out of metal, such as copper, stainless steel, or iron. The particular metal used for the piping was dependent upon the application. For example, water could be transported through copper and/or cast iron pipes. However, acidic and basic fluids had to be transported in stainless steel pipe. Some forms of metal pipes, such as copper and stainless steel, are expensive to manufacture and install. Most often, the metal pipes are either brazed or welded together. In some instances, mechanical type joints were provided for pipe connections, which include compression type fittings. In today's market, all of these arrangements are expensive to manufacture and install.
Plastic pipe overcomes many of the expenses associated with metal pipe. Plastic pipe is inexpensive to manufacture and relatively easy and inexpensive to connect together. In the case of polymeric and thermoplastic pipe materials, such as polypropylene, the pipe can be welded or fused together by providing a polypropylene sleeve with electrical heating elements embedded therein. This process is known as fusion welding. Fusion welded pipe is particularly well-suited for applications where caustic and corrosive fluids are passed through the plastic pipe. Polypropylene pipes can be joined together with mechanical seals and joint couplings as well as by fusion welding joints and couplings. In some applications, mechanical seals and joints are preferable to the fusion welding joints. In other applications, both fusion welding and mechanical seals are combined for added strength, such as those disclosed in U.S. Pat. Nos. 6,250,686; 6,450,544; and 6,680,464, which are hereby incorporated by reference.
In the past, one type of pipe joint coupling was required for fusion sealing and welding, while a different joint coupling was needed for mechanically sealed joints. This resulted in an increase in inventory required by the installer, such as the mechanical contractor or plumber, since two separate types of couplings were required, one for mechanical sealing and the other for fusion welding. Additionally, assembly and final joint preparation needed improvement in that most often, two or more individuals were needed to fabricate any of the sealed joints: one to restrain the ends of the pipes and or coupling to be joined together, and another person to weld or mechanically seal the joint.